Process for producing extruded honeycomb bodies and extrusion die

Abstract

A process is provided for producing extruded honeycomb bodies with passages, in particular as catalyst carrier bodies for the cleaning of exhaust gas from an internal combustion engine. The passages are bounded by wall regions which are at least partly provided with structures. The honeycomb body is extruded with an extrusion die in such a way that an additional relative movement between the honeycomb body and the extrusion die takes place, leading to a deformation of the wall regions of the passages. An extrusion die for producing extruded honeycomb bodies includes a multiplicity of secured profiled pins and a housing, which together form an extrusion mask. The extrusion mask is variable during the production process, so that wall regions with the structures can be formed. Honeycomb bodies which have structures in the interior that are suitable for influencing a stream of fluid flowing through can therefore be produced in a manner which is simple in terms of production engineering.

1. A process for producing extruded honeycomb bodies, which comprises:
 extruding a honeycomb body with an extrusion die forming passages bounded by wall regions and at least partly providing the wall regions with structures; 
 at least temporarily performing an oscillating movement during extrusion with the honeycomb body relative to a preferred direction of extrusion; 
 performing an additional relative movement between the honeycomb body and the extrusion die, leading to a deformation of the wall regions of the passages; and 
 at least temporarily compressing and stretching the honeycomb body during extrusion for producing a varying thickness of the wall regions. 
 
   
   
     2. The process according to  claim 1 , which further comprises at least temporarily rotating the extrusion die during extrusion. 
   
   
     3. The process according to  claim 1 , which further comprises at least temporarily rotating the honeycomb body during extrusion. 
   
   
     4. The process according to  claim 1 , which further comprises at least temporarily offsetting the extrusion die during extrusion relative to a preferred direction of extrusion. 
   
   
     5. The process according to  claim 1 , which further comprises at least temporarily offsetting the honeycomb body during extrusion relative to a preferred direction of extrusion. 
   
   
     6. The process according to  claim 1 , which further comprises directly thermally treating the honeycomb body after leaving the extrusion die. 
   
   
     7. The process according to  claim 1 , which further comprises cutting-off the honeycomb body with the structures to a desired length subsequent to extrusion. 
   
   
     8. The process according to  claim 7 , which further comprises thermally treating the honeycomb body after the cutting-off step. 
   
   
     9. A process for producing extruded honeycomb catalyst carrier bodies for the cleaning of exhaust gas from an internal combustion engine, the process which comprises:
 extruding a honeycomb catalyst carrier body with an extrusion die forming passages bounded by wall regions and at least partly providing the wall regions with structures; 
 at least temporarily performing an oscillating movement during extrusion with the honeycomb catalyst carrier body relative to a preferred direction of extrusion; and 
 performing an additional relative movement between the honeycomb catalyst carrier body and the extrusion die, leading to a deformation of the wall regions of the passages; and 
 at least temporarily compressing and stretching the honeycomb catalyst carrier body during extrusion for producing a varying thickness of the wall regions.